8/3/2019 Metabolic and Endocrine Disorder of Bone 2

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SECONDARY HYPERPARATHYROIDISM RICKETS AND OSTEOMALACIA ACROMEGALLY

Causes Chronic hypercalcemia (due to chronicrenal failure)

Rickets and osteomalaciaDeficiency / resistance to the action of vit. DHypocalcemia (due to renal failure/malabsorption)Cause of deficiency :

Lack of sun exposureDietary causes

Prolonged + excessivesecretion of growth

hormone (adenoma of ant.

lobe of pituitary after

epiphyses closed)

Clinical

features

Involvement of jawsBone changes :

ComplexMixture of osteomalacia andhyperthyroidism

Affected children :ApatheticIrritableShort attention span

Skeletal defects :Flattening of skull with frontal bossing nconspicuous lines.

Chest->classic rachitic rosary (gross beadappearance of costochondral junctions due to

enlargement of costal cartilage)

Outer curvature of sternum (pigeon breastdeformity)

Deformities of spines and limbsDental abnormalities :

Delayed eruptionEnamel hypoplasiaIncreased width of predentinLarge amounts of interglobular dentin(similar to changes in vit. D rickets-hypophosphotaemia)

Jaw involvement->deficient groth of condylar cartilage -> lack of verticalgrowth of mandibular ramus.

Renewed growth of bones ofjaws, hands, feets

Overgrowth of soft tissue(lips n nose)

Reactivation of condylargrowth centre of mandible :

EnlargementProtrusionSpacing of teeth

Histology Bony trabeculae->wide seams of uncalcified osteoid

Radiograph Similar to osteoporosis but failure in mineralization of osteoid andcartilage(in osteoporosis pt->bone is mineralized)

Extra info Rickets->in childrenOsteomalacia->in adultsAsian immigrant ini UK->dietary deficiency of vit. D :

High cereal contentwholemeal grain containing phytates->impairs calcium absorption